Orange

The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nm, and has a hue of 30° in HSV colour space. It is numerically halfway between red and yellow in a gamma-compressed RGB colour space, the expression of which is the RGB colour wheel. The complementary colour of orange is blue. Orange pigments are largely in the ochre or cadmium families, and absorb mostly blue light.

Yellow

Yellow is the colour evoked by light that stimulates both the L and M (long and medium wavelength) cone cells of the retina about equally, with no significant stimulation of the S (short-wavelength) cone cells. Light with a wavelength of 570–580 nm is yellow, as is light with a suitable mixture of red and green. Yellow's traditional RYB complementary colour is purple, violet, or indigo, while its colorimetrically defined complementary colour in both RGB and CMYK colour spaces is blue.